Class Notes (836,169)
Canada (509,675)
Anthropology (1,673)
ANT208H1 (76)
Dan Sellen (28)
Lecture

ANT208 March 15 Lecture

8 Pages
78 Views
Unlock Document

Department
Anthropology
Course
ANT208H1
Professor
Dan Sellen
Semester
Fall

Description
Reproduction, Part 2 Lecture Outline - Sex determination + sex differences - Reproductive Strategies o Sexual selection: mate choice + parenting o Sex differences: development + life history o Ecological variation: secular changes - Reproductive health, by gender o Birthing, breastfeeding o Sexual health Sex Determination Biological sex + gender = a function of phenotype Product of genetics x environment  single informational unit Ordered Process: - Chromosomal sex (fertilization) - Gonadal sex (early fetal development) - Phenotypic sex (accessory sex structures) o Chromosomal sex usually agrees with phenotypic sex o This is determined after puberty (body proportions, voice deepening in males, breast development in females = adult sex phenotypic development) Epigenetic influences - Modulate gene expression during lifespan o Early development has large effects on long term influence (just like nutrition examples)  Meaning that early exposures can influence sex development - Early development has long-term effects, larger influence - Age, education, experience, conditioning Explaining sex differences Generalized differences between male and female - Bodies - Health risk and vulnerabilities … support predictions of evolutionary theory Sexual selection theory Predicts that there would’ve been many species with an evolutionary history of gender specific selection forces that lead to gender-specific lifetime investment which may lead to conflicting needs - Gender-specific lifetime investment in o Mating effort o Reproductive effort - Gender-specific intensity of intra-sexual competition for mates Important to consider the tradeoffs between time, resources and risk spent finding a mate VS. finding a good mate (or many mates) that will help to produce good/healthy offspring There’s a tendency on male mammals to put a lot of effort into mating (production of sperm – a way to secure fertilization, male-male competition, etc) Reproductive Strategies Parental Care Mating System Fish Male only Polygamy/promiscuity - Often take fertilized eggs and put them in their mouth  good way to protect their offspring Bird Both male and female Monogamous - Fitness of offspring is largely dependent on how fast the parents can bring food to their offspring - Better for male reproductive fitness if he stays around to bring food to offspring VS. spending their time, energy and resources to find other mates Mammals Mostly female Polygyny - Males don’t seem to do anything for offspring - Most of these species – males, if they can out compete other males, will find other mates - Female mammals don’t do this b/c they invest a lot of their own resources and effort in caring for the offspring - And the fact that males don’t help take care of offspring makes it even more difficult for female/decreases female fitness further - Compensate by reducing mating effort - Males are limited by the number of females that haven’t mated Ecology + phylogeny modify how cost of reproduction affects parental investment ….. Secular trend to fewer pregnancies - Contraception o Drives a lot of difference between societies o Access to birth control - Affects ovulationary cycles - Women’s work roles - Relative value of children o Juvenile production vs cost Fecundity, fecundability, proximate determinants of fertility There are many populations with high fertility - Hidden demand for contraception that’s not being met - Education and work – people (especially women) begin to value different things - Shift in social values + opportunities - Social things > biological things There’s a lot of theories to explain demographic differences - Key insight: if you move from thinking about # of offspring vs. quality of offspring  offspring quality varies in value and is constructed across various societies How have modern environments created health problems? - Sperm production o Environmental effects? o Links between testosterone and male cancers (e.g., prostate cancer?)  There’s been lots of changes in male life histories  Problems with testosterone  is associated with lowered survival among male animals  Suppresses immune response  Testosterone  makes your body build muscle, high metabolic rates, promotes riskier behavior  So when you produce this something has to tradeoff  in this case, it’s the immune system  Men who spend more time with their children seem to have a reduction in their testosterone levels from before (changes in hormonal profile b/c of social behavior) Lifetime hormone exposure - Disparities in cancers? - Links to other outcomes? o High levels of ovarian hormones  long flows, more problems with menstruation, more PMR and cycle related mood swings, greater risk of osteoporosis, etc Aging - Age-related change in adulthood o Reproduction + diet + health + senescence (loss of function) are linked o The factors aforementioned are related o Key conceptual idea: biomedicine has treated aging as losing function – as a pathology  Evolutionary perspective: mayb
More Less

Related notes for ANT208H1

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit